Clinical significance of circulating tumor cells in blood from patients with gastric cancer

<jats:title>Abstract</jats:title><jats:p>Circulating tumor cells (<jats:styled-content style="fixed-case">CTC</jats:styled-content>) have been focused on as a target for detecting occult tumors, predicting therapeutic responses and prognoses, and monitoring postoperative recurrence in the clinical management of patients with various malignancies, including gastric cancer. Recent advances in molecular diagnostic tools have contributed to high sensitivity and specificity for the detection of <jats:styled-content style="fixed-case">CTC</jats:styled-content>. A conspicuous disparity exists in the incidence of <jats:styled-content style="fixed-case">CTC</jats:styled-content> among studies. However, a close relationship has been reported between positivity for <jats:styled-content style="fixed-case">CTC</jats:styled-content> and well‐known prognostic clinicopathological factors including depth of tumor invasion, lymph node metastasis, stage, and lymphatic and venous invasion in patients with gastric cancer. According to most studies published on the clinical impact of <jats:styled-content style="fixed-case">CTC</jats:styled-content>, the presence of <jats:styled-content style="fixed-case">CTC</jats:styled-content> negatively affects the prognosis of patients with gastric cancer. Moreover, the study of <jats:styled-content style="fixed-case">CTC</jats:styled-content> based on a meta‐analysis demonstrated their importance as a poor prognostic indicator. In clinical management, pre‐ and post‐therapeutic monitoring of <jats:styled-content style="fixed-case">CTC</jats:styled-content> using liquid biopsy may be useful for early detection of subclinical patients or disease recurrence, prediction of tumor progression, and administrative control of adjuvant chemotherapy. Although their functional properties remain unclear, molecular profiling of <jats:styled-content style="fixed-case">CTC</jats:styled-content> may contribute to the development of personalized treatment that effectively inhibits tumor progression in patients with advanced gastric cancer. We herein review the clinical significance of <jats:styled-content style="fixed-case">CTC</jats:styled-content> as a promising blood marker and therapeutic target in patients with gastric cancer.</jats:p>